Treatment of ores bearing precious metals.



IJ'NITED smarts PATENT ora ion.

JOHN COLLINS GLANCY, OF NEW YORK, N. Y.

TREATMENT OF ORES BEARING PRECIOUS METALS.

No Drawing.

To all whom it may concern."

Be it known that I, JOHN CoLLINs CLANeY, a subject of the King of GreatBritain, having declared my intention of becoming a citizen of theUnited States, at present residing at New York city, borough ofManhattan, in the county of New York and State of New York, haveinvented certain new and useful Improvements in the Treatment of OresBearing Precious Metals, of which the following is a specification.

My invention relates to a novel method of treating ores bearing theprecious metals, which method is particularly described and pointed outin the following specifications and claims.

I have discovered that the precious metals may be advantageouslyrecovered from ores containing them, whether such ores be rebellious ornon-rebellious, by the use of a cyanid solution containing a solubleiodid and nitrogen oxids. In the case of rebellious ores thosecontaining, for example, reducing agents, or tellurium, orbothnopreliminary treatment, such as roasting, is required.

In carrying my invention into practice, effecting the solution of theprecious metals, whether reducing agents and tellurium be or be notpresent, I treat the pulverized ore simultaneously with a cyanidsolution-such, for example, as potassium cyanidiodin or a solubleiodidsuch, for example, as potassium iodidand nitrogen 0xidssuch, forexample, as nitrogen peroxid. In practice with certain ores I havetreated, I have found the following proportions to answer well thepurposes of the process: a solution of one pound of potassium cyanid,one-half pound potassium iodid, and one-half pound of lime or soda,dissolved in two thousand pounds of water in the proportion of two partsof said solution to one part of ore. The amount of nitrogen peroxid tobe passed into the solutionwith or without the admixture of airis to bedetermined by titration, or otherwise. In practice I have found that aproportion equivalent to two hundred grams of nitrogen peroxid to twothousand pounds of solution gave good results, although with some oresas little as fifteen grams of nitrogen peroxid to two thousand pounds ofsolu- Specification of Letters Patent.

Application filed February 2, 1909.

Patented Sept. 2'7, 1910.

Serial No. 475,664.

tion have given excellent results. The solution may be alkaline, orneutral, or only slightly acid. The same solution can be used again andagain by keeping up the requisite strength in cyanid and nitrogenperoxid, but no further addition of potassium iodid is necessary, exceptto compensate for mechanical losses, as the nitrogen peroxid regeneratesthe iodin to begin its work over again. Between each operation it isdesirable to pass the liquor through Zinc-shavings in the ordinary wayto extract the values which it contains.

As I have said, it is not necessary in practicing the above processeswith rebellious oresthose containing, for example, reducing agents(sulfids of iron, etc.) or tellurium, or bothto roast the ore, since thesulfids do not act on the solution to decompose it, and the tellurium isdissolved simul taneously with the precious metal.

Instead of applying said nitrogen peroxid to the solution in thepresence of the ore being treated, it might be, although lessadvantageously, applied to the solution after it has been separated fromthe ore, or between successive treatments of ore, since its function isto regenerate the iodin and this function might be performed otherwisethan in the presence of ore being treated.

The cost of iodin in a commercial process would be prohibitive were itnot for the fact that in the processes above described the iodin isrepeatedly regeneratedand does the same work over and over again. Itsaction may be likened to that of a vehicle or car rier and hence it isnot substantially consumed.

It will be understood that various modifications and changes in thedescribed process may be made without departing from the spirit of myinvention and without exceeding the scope of my claims.

In a pending application Serial No. H5562 I have described the aboveprocess as an example, among others, of a generic invention, but I havenot claimed it therein specifically. I do not claim in this patent thesaid generic invention, but

IVhat I claim specifically herein is 1. The process of treatingpulverized ore containing precious metals which consists in subjectingthe ore to the action of a cyanicl solution, asoluble ioclicl andnitrogen oxicl.

2. The process of treating pulverized ore containing precious metalsWhich consists in subjecting the ore to the action of a cyaniclsolution, a soluble ioclid and nitrogen per oxid.

In testimony whereof I have signed my name to thls specification 1n thepresence of 10 tWo subscribing wltnesses.

JOHN COLLINS OLANOY.

Witnesses M. GOLDBURG, M. H. HARDING, J r.

